Phase-separating solvent composition

ABSTRACT

A pseudo-stable phase-splitting solvent composition that forms a single liquid phase when subjected to mild agitation and retains that single phase while the composition is applied to a surface, but which forms two or more laminar liquid phases promptly after being applied. A concentrated solvent film forms on the surface, under a film containing the other phase. The solvent preferably is denser than water, and the composition preferably is diluted with water. This enables the solvent to attack the surface at near full strength, and provides a water seal over the solvent film.  
     The solvent composition can be used full strength or in diluted form for cleaning, reducing the microbial population of, or degreasing a variety of surfaces, and for stripping a variety of difficult-to-remove coatings from surfaces.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation-in-part of application Ser.No. 09/560,170, filed Apr. 28, 2000.

TECHNICAL FIELD

[0002] This invention relates to solvent compositions that can be used,for example, to clean, reduce the microbial population of, or degreasesoiled surfaces, or to strip floor finishes or other coatings fromcoated surfaces.

BACKGROUND

[0003] Many concentrates and ready-to-use compositions have beenproposed for cleaning, degreasing and stripping purposes. For example,U.S. Pat. Nos. 5,080,822 (VanEenam '822); 5,080,831 (VanEenam '831);5,158,710 (VanEenam '710); 5,419,848 (VanEenam '848); 5,585,341(VanEenam '341); 5,849,682 (VanEenam '682); and 6,010,995 (VanEenam'995) describe various compositions for cleaning, degreasing orstripping. These compositions are said to be stable clear solutions,stable emulsions or stable microemulsions.

[0004] U.S. Pat. No. 4,592,787 (Johnson) describes an aqueousphotoresist stripping composition containing a lower alkyl mono ether ofa propylene glycol, a C₂₋₆alkanol, and alkanol amine, and a base.Stripping is carried out at a temperature at which the strippercomposition is a single phase, and below a temperature at which thecomposition would undergo phase separation.

[0005] U.S. Pat. No. 5,529,887 (Horn et al.) describes an aqueousphotoresist developer solution containing a diglycol monoalkyl ether, aglycol monoalkyl ether, an alkali hydroxide, and alkaline fluoride, andwater.

[0006] U.S. Pat. No. 5,637,559 (Koreltz et al.) describes compositionsfor removing urethane/acrylic floor finishes. In diluted form, thecompositions contain a phenyl-substituted alcohol, coupler and water,wherein the amount of the coupler is at least threefold the amountnecessary to completely solubilize the phenyl-substituted alcohol in thewater.

[0007] U.S. Pat. No. 5,744,440 (Liu '440) describes a mixture of a veryslightly water-soluble organic solvent and an excess of an amine oxidecoupler to fully solubilize the solvent, for hydrophobic soil and soapscum removal.

[0008] U.S. Pat. No. 5,786,319 (Pedersen et al.) describes a detergentformulation made from a glycol ether mixed with a high concentration ofa surfactant, stably dispersed in water.

[0009] U.S. Pat. No. 5,811,383 (Klier et al.) describes oil continuousmicroemulsions containing water, one or more organic solvents and ananionic surfactant.

[0010] U.S. Pat. No. 5,854,187 (Blum et al.) describes microemulsionconcentrates containing a nonionic surfactant oil phase, a continuousaqueous phase, a polar organic solvent coupling agent and a combinationof surfactants. The microemulsions are said to be thermodynamically andtemperature stable liquid systems which, when mixed with water to anappropriate solution, will invert and form stable macroemulsions,producing a bloom or milky color in the dilution medium.

[0011] U.S. Pat. No. 5,922,665 (Liu '665) describes a composition saidto be capable of removing hydrophobic soils, and containing nonionicsurfactant, a very slightly water-soluble organic solvent and water. Thecomposition is said to be translucent or hazy.

[0012] U.S. Pat. No. 5,972,874 (Libutti et al.) describes microemulsioncleaners that are said to be stable and to have a clear to slightly hazyappearance.

[0013] U.S. Pat. No. 5,997,042 (Hernandez et al.) describes a floorstripper concentrate containing a mixture of two types of solvents andan excess of a solubilizing coupler. The coupler is said to be capableof increasing the phase-stability of the stripper and the stripper issaid to be stable both as a concentrate and when diluted.

[0014] UV light curable coating compositions typically provide adesirable combination of properties including rapid cure, high gloss andgood durability. Due to these properties and their generally goodscratch and detergent resistance, UV light curable coating compositionshave been used as floor finishes. Eventually even a UV light cured floorfinish will show the effects of wear, and will require removal andrenewal. UV cured floor finishes generally are not regarded as beingremovable using conventional chemical floor stripping agents. Instead,more aggressive removal techniques such as floor sanding typically mustbe employed. This can cause potential dust problems in the workplace andcan remove a portion of the underlying floor surface. This hasdiscouraged the use of UV cured floor finishes, particularly on vinyltile, vinyl sheeting and other resilient flooring materials.

SUMMARY OF THE INVENTION

[0015] The present invention provides, in one aspect, a pseudo-stablephase-splitting cleaning, antimicrobial, degreasing or stripping solventcomposition. The term “phase” refers to a homogeneous liquid portionthat is present or that can form in a liquid system. The term “phases”refers to the presence of more than one phase in a heterogeneous liquidsystem. The term “pseudo-stable” refers to a composition that forms asingle phase when subjected to mild mixing or other agitation andretains that single phase for a sufficient period of time so that thecomposition can be applied to a surface, but which will promptly formtwo or more phases when left undisturbed. The term “phase-splinting” ismeant to describe a single phase solvent composition that forms at leasttwo laminar phases promptly after being applied atop a generallyhorizontal surface or on a generally vertical surface, whereby a filmcontaining a concentrated amount of the solvent lies between the surfaceand a film containing a much lower amount of the solvent. The term“solvent” refers to an organic material or mixture of such materialssuitable for cleaning, degreasing or stripping the desired surface. In acomposition that has undergone phase splitting, the phase containing aconcentrated amount of the solvent will be referred to as the solventphase, and the phase containing a much lower amount of the solvent willbe referred to as the dilute phase or diluting phase.

[0016] When used atop floors or other generally horizontal surfaces, thesolvent phase should be more dense than the dilute phase. When used onwalls or other generally vertical surfaces, the solvent phase shouldhave a greater tendency to cling to the surface than does the dilutephase, so that the dilute phase will be displaced from the surface bythe solvent phase.

[0017] In another aspect, the invention provides a cleaning, degreasingor stripping solvent concentrate and instructions for mixing theconcentrate with water, wherein the concentrate contains a sufficientamount of cosolvent or surfactant so that a pseudo-stablephase-splitting composition will form when the concentrate is mixed withwater according to the instructions.

[0018] In a further aspect, the invention provides an antimicrobialsolvent concentrate and instructions for mixing the concentrate withwater, wherein the concentrate contains an antimicrobial or biocidalagent dissolved or dispersed in the solvent and a sufficient amount ofcosolvent or surfactant so that a pseudo-stable phase-splittingcomposition will form when the concentrate is mixed with water accordingto the instructions.

[0019] In a further aspect, the invention provides a split-phasecleaning, antimicrobial, degreasing or stripping agent atop a surface,wherein a non-aqueous film phase comprising a solvent that is denserthan water lies adjacent the surface and under an aqueous film phase.This enables the solvent film to attack the surface at near fullstrength, and provides a water seal over the solvent film.

[0020] In another aspect, the invention provides a method of removing acoating or a soil from a surface, comprising applying to the surface apseudo-stable mixture containing water, polar solvent that is denserthan water, and a sufficient amount of cosolvent or surfactant so thatthe mixture phase-separates following application of the mixture to thesurface, allowing the mixture to phase-separate, allowing the polarsolvent to soften or dissolve the coating or soil, and removing thesoftened coating or soil.

[0021] In yet another aspect, the invention provides a method ofremoving soil from or reducing the antimicrobial population of a surfaceby contacting the surface with an aqueous dispersion of a solvent whichforms split phases following contact with the surface, wherein a filmphase containing primarily solvent lies adjacent the surface and under afilm phase containing primarily water.

DETAILED DESCRIPTION

[0022] The solvent compositions of the invention can be applied to avariety of materials on a variety of surfaces. For example, the solventcompositions can be used to remove paints, finishes, photoresists, inks,oils, food soils and other coatings from a variety of surfaces,including hard surfaces and soft surfaces having smooth or poroustopography. Suitable hard surfaces include, for example, architecturalsurfaces (e.g., floors, walls, windows, sinks, tables, counters andsigns); eating utensils; hard-surface medical or surgical instrumentsand devices; hard-surface packaging; and transportation vehicles andvehicle components (e.g., automobiles, motorcycles, bicycles, andaircraft; and wheels, gears, engines and other parts therefor). Suchhard surfaces can be made from a variety of materials comprising, forexample, ceramics, metals, woods or hard plastics. Suitable softsurfaces include, for example, wallpaper; carpet; soft-surface medicalor surgical instruments and devices; and soft-surface packaging. Suchsoft surfaces can be made from a variety of materials comprising, forexample, paper, fiber, woven or nonwoven fabric or soft plastics. Thecompositions of the invention can also be applied to soft surfaces suchas food substances and skin. In addition, the compositions of theinvention can be used to reduce the microbial population of surfaces inareas such as kitchens, bathrooms, factories, hospitals, dental offices,food plants, etc.

[0023] When left undisturbed on a surface, the solvent compositions ofthe invention form two or more liquid film phases, with the solventphase lying between the surface and the dilute phase. For example, onfloors or other generally horizontal surfaces, the solvent phase willlie atop the floor (or atop a coating on the floor) and under the dilutephase or phases. On walls or other generally vertical surfaces, thesolvent phase will lie adjacent the surface and under the dilute phaseor phases.

[0024] For simplicity, the remainder of this specification will discusscompositions that form two-phase systems, it being understood thatcompositions forming three or more phases could be employed if desired.

[0025] Although a variety of materials could be used for the dilutephase or phases, preferably the dilute phase contains mainly water. Theremainder of this specification will primarily discuss the use of waterto form the dilute phase, it being understood that other suitableliquids could be substituted for water if desired.

[0026] The compositions of the invention preferably are formulated andsold as solvent concentrates. If desired, the concentrates can be usedfull-strength as a cleaner, antimicrobial agent, degreaser or stripper.However, the concentrates typically will be diluted with a liquid (e.g.,water) that subsequently forms the dilute phase. Preferably theconcentrate forms a single phase before such dilution and remains sowhile stored in the container in which it will be sold. When combinedwith water or other desired diluting liquid at an appropriate dilutionlevel and subjected to mild agitation (e.g., by stirring the compositionin a bucket, pumping, spraying or using a mop, cloth or other suitableimplement), the compositions of the invention form a pseudo-stablesolution or dispersion. The composition should remain in thepseudo-stable state for a sufficiently long period so that thecomposition can be applied to a surface before the onset of phaseseparation. The pseudo-stable state need only last for a few secondswhen suitably rapid application techniques such as spraying areemployed, or when agitation during application is employed. Thepseudo-stable state desirably lasts for at least one minute or moreafter mixing and while the composition is stored in a bucket or othersuitable vessel, and preferably lasts for five minutes or more aftermixing. If a mop or other absorbent applicator, sprayer or pump is usedto apply the compositions of the invention, then normal refilling orreplenishment of the applicator (e.g., by dipping the mop in a mopbucket) will provide sufficient agitation of the composition to preserveits pseudo-stable state during application.

[0027] Following application to a surface, the composition undergoesphase-splitting. Preferably this will occur relatively soon afterapplication, e.g., in less than 10 minutes, more preferably in less than5 minutes and most preferably in less than 2 minutes.

[0028] The compositions of the invention are particularly preferred foruse in stripping floor finishes. When so used, the compositions of theinvention could be referred to as “strip agents”. The strip agents ofthe invention are especially preferred for removing laminate floorfinishes having a strippable intermediate coating on a substrate, and astrip agent-permeable coating or topcoat on the intermediate coating,wherein the topcoat is less strippable and more wear-resistant than theintermediate coating. In a preferred use for the strip agents of theinvention, the substrate is a floor, the topcoat is a UV curable floorfinish, the intermediate coating is an acrylic or urethane floor finish,and the strip agent contains benzyl alcohol.

[0029] The compositions of the invention can contain a variety ofsolvents. The solvent preferably is insoluble, or only sparinglysoluble, in the diluting liquid. Thus for compositions intended to bediluted with water, the solvent preferably will have a water solubilityless than about 5% by weight, more preferably less than about 3% byweight, and most preferably less than about 1% by weight (all parts andpercentages in the remainder of this specification will be by weightunless otherwise indicated).

[0030] In general, the solvent is selected based upon thecharacteristics of the surface to which the solvent will be applied andupon the nature of the coating, soil or other material that will becontacted on and optionally removed from that surface. Polar solvents,or solvents capable of hydrogen bonding, typically will perform well ona variety of surfaces and materials and thus are preferred. Forapplications in which the solvent is intended to permeate through adurable overlayer or topcoat in order to attack and dissolve or softenan underlying layer, the solvent preferably has a high permeation ratethrough the overlayer. Compositions and methods employing such topcoatsand underlying layers are described in the above-mentioned applicationSer. No. 09/560,170, filed Apr. 28, 2000, and in application Ser. No.[Attorney Docket No. 103-1334.01], filed on even date herewith, bothincorporated by reference herein. Preferably, the solvent also has ahigh flashpoint (e.g., greater than about 30° C., more preferablygreater than about 50° C., and most preferably greater than about 100°C.), low odor and low toxicity.

[0031] Preferred solvents having a density greater than water (and thusespecially useful in compositions that will be diluted with water andapplied atop horizontal or generally horizontal surfaces) includeacetamidophenol (specific gravity 1.027); acetanilide (specific gravity1.219; water solubility <1%); acetophenone (specific gravity 1.0238;water solubility <1%); [2-acetyl-1-methylpyrrole (specific gravity1.04); benzyl acetate (specific gravity 1.0515; water solubility <1%);benzyl alcohol (specific gravity 1.0413; water solubility <1%); benzylbenzoate (specific gravity 1.118; water solubility <1%);benzyloxyethanol (specific gravity 1.07; water solubility <1%); ethersor hydroxyethers such as ethylene glycol phenyl ether (specific gravity1.104; water solubility 2.3%; commercially available as “Dowanol EPh”from Dow Chemical Co.) and propylene glycol phenyl ether (specificgravity 1.063; water solubility 1.1%; commercially available as “DowanolPPh” from Dow Chemical Co.); essential oils (e.g., benzaldehyde, pinenes(alphas, betas, etc.), terpineols, terpinenes, carvone, cinnamealdehyde,borneol and its esters, citrals, ionenes, jasmine oil, limonene,dipentene, linalool and its esters), dibasic esters such as dimethyladipate, dimethyl succinate, dimethyl glutarate (often available in amix with specific gravities greater than 1.00; including productsavailable under the trade designations DBE, DBE-3, DBE-4, DBE-5, DBE-6,DBE-9, DBE-IB, and DBE-ME from DuPont Nylon), dimethyl malonate, diethyladipate, diethyl succinate, diethyl glutarate, dibutyl succinate, anddibutyl glutarate; dialkyl carbonates such as dimethyl carbonate,diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, anddibutyl carbonate; and phthalate esters such as dibutyl phthalate,diethylhexyl phthalate, and diethyl phthalate. Benzyl alcohol, essentialoils, dibasic esters, dialkyl carbonates, ethylene glycol phenyl etherand propylene glycol phenyl ether are particularly preferred solvents.Mixtures of solvents can be used if desired.

[0032] The compositions of the invention should contain sufficientsolvent to provide the desired rate and type of cleaning, microbialreduction, degreasing or stripping. Usually, solvent concentrates of theinvention will contain at least about 5% solvent, preferably at leastabout 25% solvent, more preferably at least about 65% solvent, and mostpreferably about 75 to about 95% solvent.

[0033] The compositions of the invention can contain one or morecosolvents or surfactants to assist in providing the desiredpseudo-stable and phase-splitting behavior. In general, cosolvents orsurfactants that are relatively inefficient or ineffective (with respectto their ability to solubilize or disperse the solvent in the dilutephase) are preferred over cosolvents or surfactants that are moreefficient or effective. This differs from the approach normally takenwhen formulating compositions containing cosolvents or surfactants.Normally, cosolvents and surfactants are selected for their ability topromote formation of stable solutions or dispersions.

[0034] A variety of cosolvents can be employed. In general, thecosolvent is selected based upon the characteristics of the chosensolvent and the solubility of the chosen solvent in the dilute phase.For compositions in which water serves as the dilute phase, thecosolvent generally will have higher water solubility than the watersolubility of the chosen solvent. Preferably, the cosolvent has a highflashpoint (e.g., greater than about 30° C., more preferably greaterthan about 50° C., and most preferably greater than about 100° C.), lowodor and low toxicity.

[0035] Preferred cosolvents include 2-(2-aminoethoxy)ethanol,monoethanolamine, diethanolamine, triethanolamine, amyl acetate, amylalcohol, butanol, 3-butoxyethyl-2-propanol, butyl acetate, n-butylpropionate, cyclohexanone, diacetone alcohol, diethoxyethanol,diethylene glycol methyl ether, diethylene glycol n-butyl ether,diisobutyl carbinol, diisobutyl ketone, dimethyl heptanol, dipropyleneglycol n-butyl ether, dipropylene glycol methyl ether, dipropyleneglycol propyl ether, dipropylene glycol tert-butyl ether, ethanol, ethylacetate, 2-ethylhexanol, ethyl propionate, ethylene glycol butyl ether,ethylene glycol methyl ether acetate, hexanol, isobutanol, isobutylacetate, isobutyl heptyl ketone, isophorone, isopropanol, isopropylacetate, methanol, methyl amyl alcohol, methyl n-amyl ketone,2-methyl-1-butanol, methyl ethyl ketone, methyl isobutyl ketone,1-pentanol, n-pentyl propionate, 1-propanol, n-propyl acetate, n-propylpropionate, propylene glycol n-butyl ether, propylene glycol ethylether, propylene glycol methyl ether, propylene glycol n-propyl ether,tripropylene glycol methyl ether and tripropylene glycol n-butyl ether.Ethylene glycol butyl ether and dipropylene glycol n-butyl ether areparticularly preferred cosolvents. Mixtures of cosolvents can be used ifdesired.

[0036] Commercially available cosolvents (all of which are availablefrom Union Carbide Corp.) include Butoxyethyl PROPASOL™, Butyl CARBITOL™acetate, Butyl CARBITOL™, Butyl CELLOSOLVE™ acetate, Butyl CELLOSOLVE™,Butyl DIPROPASOL™, Butyl PROPASOL™, CARBITOL™ PM-600, CARBITOL™ LowGravity, CELLOSOLVE™ acetate, CELLOSOLVE™, Ester EEP™, Filmer IBT™,Hexyl CARBITOL™, Hexyl CELLOSOLVE™, Methyl CARBITOL™, Methyl CELLOSOLVE™acetate, Methyl CELLOSOLVE™, Methyl DIPROPASOL™, Methyl PROPASOL™acetate, Methyl PROPASOL™, Propyl CARBITOL™, Propyl CELLOSOLVE™, PropylDIPROPASOL™ and Propyl PROPASOL™.

[0037] The compositions of the invention preferably should not containexcessive amounts of cosolvent. Instead, the amount of cosolventpreferably is just sufficient to provide the desired pseudo-stable andphase-splitting behaviors. Larger amounts of cosolvent will tend tocause the composition to exhibit long term stability rather thanpseudo-stability, and will delay (or prevent entirely) the attainment ofsplit phases. Usually, the solvent concentrates of the invention willcontain 0 to about 50% cosolvent, more preferably 0 to about 25%cosolvent, and most preferably 0 to about 20% cosolvent.

[0038] A variety of surfactants can be employed. In general, thesurfactant's identity and use level is selected based upon thecharacteristics of the chosen solvent and the solubility of the chosensolvent in the dilute phase. For compositions in which water serves asthe dilute phase, the surfactant preferably will have an HLB valuegreater than or equal to about 13, or less than or equal to about 6.This value reflects the above-noted preference for employing surfactantsthat are relatively inefficient or ineffective as emulsifiers.Preferably, the surfactant does not tend to cause formation of insolubledeposits, and has low odor and low toxicity. Mixtures of surfactants canbe used if desired.

[0039] Preferred anionic surfactants include C₆-C₂₄ alkylbenzenesulfonates; C₆-C₂₄ olefin sulfonates; C₆-C₂₄ paraffin sulfonates; cumenesulfonate; xylene sulfonate; C₆-C₂₄ alcohol sulfates (preferably C₆-C₁₂alcohol sulfates); and C₆-C₂₄ alcohol ether sulfates having 1 to about20 ethylene oxide groups.

[0040] Preferred nonionic surfactants include C₆-C₂₄ alcohol ethoxylates(preferably C₆-C₁₄ alcohol ethoxylates) having 1 to about 20 ethyleneoxide groups (preferably about 9 to about 20 ethylene oxide groups);C₆-C₂₄ alkylphenol ethoxylates (preferably C₈-C₁₀ alkylphenolethoxylates) having 1 to about 100 ethylene oxide groups (preferablyabout 12 to about 20 ethylene oxide groups); and C₆-C₂₄alkylpolyglycosides (preferably C₆-C₂₀ alkylpolyglycosides) having 1 toabout 20 glycoside groups (preferably about 9 to about 20 glycosidegroups).

[0041] Preferred cationic surfactants include quaternary amine compoundshaving the formula:

[0042] where R, R′, R″ and R″′ are each an alkyl, aryl or aralkyl groupthat can optionally contain one or more P, O, S or N heteroatoms, and Xis F, Cl, Br, I or an alkyl sulfate.

[0043] Preferred amphoteric surfactants include amine oxide compoundshaving the formula:

[0044] where R, R′, R″ and R″′ are each a C₆-C₂₄ alkyl, aryl or aralkylgroup that can optionally contain one or more P, O, S or N heteroatoms.

[0045] Another class of preferred amphoteric surfactants includesbetaine compounds having the formula:

[0046] where R, R′, R″ and R″′ are each a C₆-C₂₄ alkyl, aryl or aralkylgroup that can optionally contain one or more P, O, S or N heteroatoms,and n is about 1 to about 10.

[0047] The compositions of the invention should not contain excessiveamounts of surfactant. Instead, the amount of surfactant should be justsufficient to provide the desired pseudo-stable and phase-splittingbehaviors. Larger amounts of surfactant will tend to cause thecomposition to exhibit permanent stability rather than pseudo-stability,will prolong (or prevent entirely) the attainment of split phases, andmay cause the formation of undesirable deposits or other soils on thesurface to which the compositions are applied. Usually, the solventconcentrates of the invention will contain no more than about 10%surfactant, more preferably 0 to about 3% surfactant and most preferably0 to about 1% surfactant. Most preferably, the compositions of theinvention are substantially surfactant-free.

[0048] The solvent compositions of the invention can optionally containantimicrobial or biocidal agents that will dissolve or disperse in thesolvent or dilute phase upon mixing. Desirably, the antimicrobial agentwill preferentially dissolve or disperse in the solvent phase ratherthan in the dilute phase. Suitable antimicrobial agents includecarboxylic acids (e.g., butyric acid, heptanoic acid, octanoic acid,nonanoic acid, and decanoic acid), sulfonic acids (e.g., dodecylbenzenesulfonic acid), active halogen compounds (e.g., sodium hypochlorite orsodium chlorite), active oxygen compounds (e.g., hydrogen peroxide, orequilibrium derived or isolated peracids such as peracetic acid,perheptanoic acid, peroctanoic-acid, performic acid, percitric acid,perglycolic acid, perlactic acid, perbenzoic acid, and monoesterperacids derived from diacids such as adipic, succinic, glutaric, ormalonic acid and mixtures thereof, and mixtures thereof), phenolicderivatives (e.g., o-phenyl phenol, o-benzyl-p-chlorophenol andtert-amyl phenol), quaternary ammonium compounds (e.g.,alkyldimethylbenzyl ammonium chloride, dialkyldimethyl ammonium chlorideand mixtures thereof), and mixtures of such antimicrobial or biocidalagents, in an amount sufficient to provide the desired degree ofmicrobial protection. Most of the aforementioned antimicrobial orbiocidal agents having about 1-6 carbons, or an ionic charge, would bemostly soluble in the dilute phase; those with higher carbon numberswould generally be more solvent-phase soluble. In either case it ispreferred to use antimicrobials that can be drawn into the solvent phaseor onto surfaces during phase separation.

[0049] Compositions of the invention containing such antimicrobial orbiocidal agents appear to have substantially greater effectiveness thancorresponding compositions that do not exhibit phase-splitting behavior.If present in the concentrate, the antimicrobial or biocidal agentpreferably is about 0.01 to about 30% of the concentrate, morepreferably about 0.1 to about 10% and most preferably about 0.5 to about5%.

[0050] If desired, the solvent compositions of the invention can containvarious adjuvants such as chelants, builders, thickeners, fragrances,dyes, pH adjusters, anticorrosion additives and antirust additives. Thetypes and amounts of such adjuvants will be apparent to those skilled inthe art.

[0051] Although the solvent concentrates of the invention can beformulated to include the dilute phase liquid (e.g., water), preferablythe concentrate contains little or no diluting liquid. The dilutingliquid preferably is added at the time of use. A variety of dilutionratios can be employed, so long as the diluted composition exhibits thedesired pseudo-stable and phase-splitting behaviors and is effectivewhen applied to the chosen surface. The ingredients in the concentratecan represent about 1 to about 99% of the diluted mixture, morepreferably about 5 to about 50%, and most preferably about 6 to about25%.

[0052] Although no longer commercially available, an aqueous strippingagent concentrate previously sold in Canada as Fuller Formula 3100™Super Concentrate (Fuller Brush, Québec) could be used in the presentinvention, if employed at a dilution ratio not recommended in theproduct instructions. Fuller Formula 3100™ Super Concentrate is believedto have contained about 49% benzyl alcohol, 17% monoethanolamine, 10%sodium decyldiphenyl ether disulfonate and 24% water. Dilution of theconcentrate at a 1:20 concentrate:water ratio was recommended on theproduct instructions. At that dilution ratio, the resulting mixtureformed a stable single-phase solution. However, if diluted at asufficiently larger concentrate:water ratio (e.g., 1:10), the resultingmixture forms a pseudo-stable dispersion that will undergo phasesplitting when applied to a substrate and allowed to stand for a fewminutes.

[0053] Selection of the types and amounts of ingredients in the solventcompositions of the invention, and choice of an appropriate dilutionratio, preferably is accomplished by evaluating the cleaning,disinfecting, degreasing or stripping performance of the compositionunder representative test conditions. In general, stripping is moredemanding than degreasing and most forms of cleaning or disinfecting.Stripping of UV-curable coatings is especially difficult, and thusrepresents a useful “worst-case” basis for such an evaluation. Strippingperformance can be evaluated by coating and stripping tiles using theSubstrate Coating Procedure and Stripping Evaluation Method (7 pointscale) set out below in the Example section. Preferably, thecompositions of the invention exhibit a rating of at least 3, and morepreferably at least 6, when so evaluated.

[0054] The permeability of individual strip agent formulations of theinvention through a multilayer coating can be graphically illustrated byapplying several marked coats of metal-catalyzed acrylic floor finishand UV-curable coating to light colored floor tiles. A laundry markingpen or other suitable permanent felt marking pen is used to number eachcoat prior to application of the next coat. When the strip agent isapplied to the resulting multilayer laminate construction, the appliednumbers will fade away and disappear in the order in which theindividual coats dissolve.

[0055] The compositions of the invention can be applied to surfacesusing a variety of methods, including spraying, brushing, roll coatingand flood coating. Mop application is preferred for coating floors. If adurable coating (e.g., a UV-crosslinked floor finish) is to be removedusing a composition of the invention, removal can be assisted byapplying the strip agent and then abrading the coating with a suitablymild abrasive (e.g., a green or black Scotch-Brite™ Floor Maintenancepad from 3M). The strip agent should be allowed to stand for a suitabletime (e.g., for a minute or more, and typically between about 5 andabout 30 minutes) while it forms split phases and attacks the coating.After the coating softens sufficiently (and after subjecting it tooptional mild abrasion), the coating and strip agent can be removed fromthe floor or other surface using a variety of techniques includingvacuuming, mopping or wiping. After removal of the coating and stripagent, the floor or other surface can optionally be rinsed with water ora suitable solvent to remove any remaining residue. The substrate can beallowed to dry and new layers of coating can be applied to renew thefinish.

[0056] The compositions of the invention can be sold in the form of akit containing the composition (e.g., a strip agent), together withsuitable directions for carrying out the method of the invention. Thekit can optionally contain one or more coating compositions that can becleaned or removed using a composition of the invention. The kit canalso optionally contain undercoat materials (e.g., leveling coatings)that can be applied to a substrate before application of the coatingcomposition, overcoat materials (e.g., wax finishes) that can be appliedatop the coating composition, and one or more applicators that can beused to apply the compositions of the invention to a surface.

[0057] The invention is further illustrated in the followingnon-limiting examples, in which all parts and percentages are by weightunless otherwise indicated. In the examples the following procedureswere employed:

Substrate Coating Procedure

[0058] A set of 150 mm square white or black vinyl composite floor tilesfrom Armstrong Tile or from American Biltrite Limited was coated with 2coats of a waterborne metal-catalyzed acrylic floor finish (GemstarLaser™, Ecolab Inc.) applied at a 20% solids level. Each coat wasallowed to air dry before application of the second coat. The totalcoating thickness after the second coat had dried was about 10micrometers (at 5 micrometers per coat). The coated tiles were nextcoated with 2 coats of a waterborne UV curable coating formulationobtained from UV Coatings Limited (identified as “936-66-2”, a 75:25blend of an aliphatic polyester urethane and an acrylic resin) appliedat a 30% solids level. Each coat was allowed to air dry beforeapplication of the next coat. The total dried coating thickness forthese two UV curable coats was about 15 micrometers (at 7.5 micrometersper coat), yielding a combined coating thickness of about 25micrometers. The coated tiles were passed through a UV curing apparatuscontaining an H bulb mercury vapor lamp operated at 1935 joule/sec percm² and 4.9 meters per minute to cure the UV-curable topcoat layers.

EXAMPLE 1

[0059] A strip agent preconcentrate (“Preconcentrate A”) was prepared bystirring 30 parts propylene glycol phenyl ether in a vessel and adding30 parts diethylene glycol monobutyl ether (Butyl CELLOSOLVE™, UnionCarbide Corp.) and 30 parts dipropylene glycol N-butyl ether. Themixture was stirred until it became uniform in appearance. Next, 10parts of a C12-14 linear alcohol (9 mole) ethoxylate surfactant(Surfonic™ 24-9 ethoxylated alcohol, Huntsman Chemical) was added withstirring. The mixture formed a clear solution.

[0060] Preconcentrate A was combined with varying amounts of benzylalcohol to form a series of 5 strip agent concentrates. The strip agentconcentrates were diluted with water at a 1:9 concentrate:water ratio toform a series of 5 strip agents. All 5 strip agents formed cloudysolutions after mixing. The presence or absence of pseudo-stability wasnoted by observing whether phase-separation occurred within 5 minutesafter mixing. A shorter or longer period could be chosen, but as notedabove, 5 minutes represents a preferred pseudo-stability time.

[0061] The strip agents were applied to a UV-cured floorfinish/metal-catalyzed floor finish laminate that had been coated onvinyl composite floor tiles using the Substrate Coating Procedure. Thestrip agent containing only benzyl alcohol and water separated veryrapidly unless stirred continuously, and without such stirring could notbe applied as a homogenous dispersion. The strip agents were visuallyobserved to determine whether split phases formed following applicationof the strip agent to the tiles. Stripping performance was evaluated byallowing the strip agent to stand on the coated tiles for 10 minutes,abrading the strip agent with a green Scotch-Brite™ Floor Maintenancepad from 3M, attempting to remove the finish by mopping, and visuallyrating the degree of finish removal as “None”, “Poor”, “Partial” or“Complete”. Set out below in Table I are the Run Number, ingredients ineach strip agent concentrate, appearance upon mixing, presence orabsence of pseudo-stability and split phases, and stripping performancefor each strip agent and for a pure water control. TABLE I Pseudo-Precon- Benzyl Stability Run centrate Alcohol, Appear- for 5 SplitStripping No. A, parts parts ance Minutes? Phases? Performance 1-1 100 0Cloudy No No Partial 1-2 75 25 Cloudy No No Partial 1-3 50 50 Cloudy NoPartial Partial 1-4 25 75 Cloudy Yes Yes Complete 1-5 0 100 Cloudy NoYes Complete 1-6 0 0 Clear No No None

[0062] The results in Table I show that a pseudo-stable, phase splittingcomposition stripped a hard-to-remove UV-cured finish, and provided awater seal during stripping. Stripping could also be carried out using a90:10 mixture of water and benzyl alcohol, but the composition could notbe applied as a homogenous dispersion unless it was continuouslystirred.

EXAMPLE 2

[0063] Using the method of Example 1, several 90:10 mixtures of benzylalcohol and various emulsifying surfactants were combined to form stripagent concentrates. The strip agent concentrates were diluted with waterat a 1:9 concentrate:water ratio to form a series of strip agents. Allthe strip agents formed cloudy solutions after mixing. The presence orabsence of pseudo-stability was noted for each strip agent.

[0064] The strip agents were applied to a UV-cured floorfinish/metal-catalyzed floor finish laminate and evaluated using themethod of Example 1. Set out below in Table II are the Run Number,emulsifying surfactant (if any) added to each strip agent, appearanceafter mixing, presence or absence of pseudo-stability and split phases,and stripping performance for each strip agent. TABLE II Pseudo-Stability Run for 5 Split Stripping No. Surfactant Appearance Minutes?Phases? Performance 2-1 NPE¹ Cloudy No No Partial 2-2 DNPE² Cloudy No NoNone 2-3 L/M³ Cloudy No No Partial 2-4 SXS⁴ Cloudy No No None 2-5 HG⁵Cloudy No No None 2-6 None Clear No Yes Complete

[0065] The results in Table II show that addition of excess surfactantprevented the formation of split phases and harmed strippingperformance.

EXAMPLE 3

[0066] Using the method of Example 1, several strip agent concentrateswere prepared by combining Preconcentrate A with varying amounts ofmethylethanolamine (“MEA”) and benzyl alcohol. The strip agentconcentrates were diluted with water at a 1:9 concentrate:water ratio toform a series of strip agents. The appearance after mixing was noted foreach strip agent.

[0067] The strip agents were applied to a UV-cured floorfinish/metal-catalyzed floor finish laminate and evaluated using themethod of Example 1. Set out below in Table III are the Run Number,ingredients in each strip agent concentrate, presence or absence ofsplit phases, and stripping performance for each strip agent. TABLE IIIPrecon- Benzyl Run centrate MEA, Alcohol, Appear- Split Stripping No. A,parts parts parts ance Phases? Performance 3-1  100 0 0 Cloudy NoPartial 3-2  75 25 0 Cloudy No Partial 3-3  50 50 0 Cloudy No Partial3-4  25 75 0 Cloudy No Poor 3-5  0 100 0 Clear No Poor 3-6  0 75 25Clear No None 3-7  0 50 50 Clear No None 3-8  0 25 75 Cloudy No None3-9  0 0 100 Cloudy Yes Complete 3-10 50 25 25 Milky No None 3-11 25 5025 Cloudy No None 3-12 25 25 50 Milky No None 3-13 75 12 13 Cloudy NoNone 3-14 12 75 13 Cloudy No None 3-15 12 13 75 Milky No None 3-16 33 3334 Milky No None

[0068] The results in Table III show that a number of clear, cloudy ormilky strip agent compositions could be formed, but that completestripping performance was not obtained unless the strip agent exhibitedphase splitting following application to a surface.

[0069] Various modifications and alterations of this invention will beapparent to those skilled in the art without departing from the scopeand spirit of this invention. It should be understood that thisinvention is not limited to the illustrative embodiments set forthabove.

We claim:
 1. A pseudo-stable phase-splitting cleaning, antimicrobial,degreasing or stripping solvent composition.
 2. A composition accordingto claim 1, wherein the solvent comprises a polar solvent.
 3. Acomposition according to claim 2, wherein the polar solvent comprises anether, an aromatic alcohol, a dialkyl diester, or mixtures thereof.
 4. Acomposition according to claim 2, wherein the polar solvent comprises atleast one of benzyl alcohol, ethylene glycol phenyl ether, propyleneglycol phenyl ether, propylene carbonate, phenoxyethanol, dimethyladipate, dimethyl succinate, dimethyl glutarate, dimethyl malonate,diethyl adipate, diethyl succinate, diethyl glutarate, dibutyl adipate,dibutyl succinate, dibutyl glutarate, or mixtures thereof.
 5. Acomposition according to claim 1, wherein the composition is anantimicrobial composition or contains another antimicrobial or biocidalagent dissolved or dispersed in the solvent.
 6. A composition accordingto claim 1, wherein the composition contains water, and the solvent ismore dense than water.
 7. A composition according to claim 6, whereinwhen the composition is mixed it has a pseudo-stable emulsified statethat lasts for at least one minute or more after mixing while thecomposition is stored in a bucket or other vessel, and wherein when thecomposition is applied to a surface it will phase-separate to form apredominantly solvent-containing layer on the surface.
 8. A compositionaccording to claim 7 wherein the surface comprises a hard surface, softsurface, porous surface, food substance or skin.
 9. A compositionaccording to claim 8, wherein the surface comprises an architecturalsurface.
 10. A composition according to claim 9, wherein thearchitectural surface comprises a floor, wall, window, sink, table,counter or bathroom.
 11. A composition according to claim 8 wherein thesurface comprises a medical or surgical instrument or device, atransportation vehicle, or an eating utensil.
 12. A compositionaccording to claim 8 wherein the surface comprises a porous surface. 13.A composition according to claim 12 wherein the porous surface comprisespaper or fabric.
 14. A composition according to claim 8 wherein thesurface comprises a floor.
 15. A composition according to claim 14,wherein the composition will phase-separate within two minutes afterapplication.
 16. A composition according to claim 7, wherein the surfacecomprises a crosslinked polymeric topcoat.
 17. A composition accordingto claim 6, wherein the solvent has a water solubility less than about10% by weight.
 18. A composition according to claim 6, wherein thesolvent has a water solubility less than about 5% by weight.
 19. Acomposition according to claim 6, wherein the solvent has a watersolubility less than about 1% by weight.
 20. A composition according toclaim 1, further comprising cosolvent or surfactant.
 21. A compositionaccording to claim 20, wherein the cosolvent has greater watersolubility than the solvent.
 22. A composition according to claim 20,containing water and at least about 10% solvent.
 23. A compositionaccording to claim 20, containing water and at least about 50 weight %solvent.
 24. A composition according to claim 20, containing about 75weight % to about 95 weight % solvent.
 25. A composition according toclaim 24, wherein the solvent comprises benzyl alcohol, ethylene glycolphenyl ether, phenoxyethanol, or propylene glycol phenyl ether, thecomposition contains about 5 weight % to about 25 weight % cosolventcomprising diethylene glycol monobutyl ether or dipropylene glycolN-butyl ether, and the composition contains no more than about 3 weight% surfactant.
 26. A cleaning, degreasing, antimicrobial or strippingagent comprising a concentrate and instructions for mixing theconcentrate with water, the concentrate comprising a polar solvent thatis denser than water and a sufficient amount of cosolvent or surfactantso that a pseudo-stable phase-splitting composition will form when theconcentrate is mixed with water according to the instructions.
 27. Anagent according to claim 26, wherein the pseudo-stable state lasts forat least one minute or more after mixing and while the composition isstored in a bucket or other suitable vessel.
 28. An agent according toclaim 26, wherein the solvent comprises an ether, hydroxyether, orbenzyl alcohol.
 29. An agent according to claim 26, wherein the solventcomprises benzyl alcohol, ethylene glycol phenyl ether, phenoxyethanolor propylene glycol phenyl ether.
 30. An agent according to claim 26,wherein after application of the agent to a surface a predominantlypolar solvent layer will form on the surface and a predominantly aqueouslayer will form on the polar solvent layer.
 31. An agent according toclaim 30, wherein the splitting occurs within two minutes afterapplication.
 32. An agent according to claim 30, wherein the surfacecomprises a hard surface, soft surface, porous surface, food substanceor skin.
 33. An agent according to claim 32, wherein the surfacecomprises an architectural surface.
 34. An agent according to claim 33,wherein the architectural surface comprises a floor, wall, window, sink,table, counter or bathroom.
 35. An agent according to claim 32, whereinthe surface comprises a medical or surgical instrument or device, atransportation vehicle, or an eating utensil.
 36. An agent according toclaim 32, wherein the surface comprises a porous surface.
 37. An agentaccording to claim 37, wherein the porous surface comprises paper orfabric.
 38. An agent according to claim 32, wherein the surfacecomprises a floor.
 39. An agent according to claim 32, wherein thesurface comprises a crosslinked polymeric topcoat.
 40. An agentaccording to claim 39, wherein the topcoat was UV-crosslinked and withina time no greater than 30 minutes after application the agent willsoften the topcoat sufficiently so that the topcoat can be removed fromthe surface.
 41. An agent according to claim 40, wherein the time is nogreater than 15 minutes.
 42. An agent according to claim 32, wherein thesurface is porous.
 43. An agent according to claim 32, wherein thesurface comprises a transportation vehicle or component thereof.
 44. Anagent according to claim 26, wherein the solvent is sparingly soluble orinsoluble in water.
 45. An agent according to claim 26, wherein thecosolvent comprises diethylene glycol butyl ether, or dipropylene glycolbutyl ether.
 46. An agent according to claim 26, wherein amount ofcosolvent is less than about 25 weight % of the concentrate.
 47. Anagent according to claim 26, wherein the surfactant has an HLB ratiogreater than about 13 or less than about
 6. 48. An agent according toclaim 26, wherein the concentrate is substantially surfactant-free. 49.An antimicrobial composition comprising a concentrate and instructionsfor mixing the concentrate with water, the concentrate comprising apolar solvent that is denser than water, an antimicrobial or biocidalagent dissolved or dispersed in the solvent, and, optionally, acosolvent or surfactant, wherein a pseudo-stable phase-splittingcomposition will form when the concentrate is mixed with water accordingto the instructions.
 50. An antimicrobial composition according to claim49, wherein the antimicrobial or biocidal agent comprises at least oneof a carboxylic acid, sulfonic acid, active halogen compound, activeoxygen compound, phenolic derivative or quaternary ammonium compound.51. An antimicrobial composition according to claim 49, wherein theantimicrobial or biocidal agent is about 1 to about 50% of theconcentrate.
 52. A floor finishing and floor finish removal kitcomprising a UV-crosslinked composition for applying a durable finish toa floor, and a stripping agent according to claim 1 for removing thedurable finish.
 53. A method of removing a coating or a soil from asurface, comprising applying to the surface a pseudo-stable mixturecontaining water, polar solvent that is denser than water, and asufficiently low amount of cosolvent or surfactant so that the mixturephase-separates following application of the mixture to the surface,allowing the mixture to phase-separate, allowing the polar solvent tosoften or dissolve the coating or soil, and removing the softenedcoating or soil.
 54. A method according to claim 53, wherein the surfacecomprises a hard surface, soft surface, porous surface, food substance,or skin.
 55. A method according to claim 54, wherein the surfacecomprises an architectural surface.
 56. A method according to claim 55,wherein the architectural surface comprises a floor, wall, window, sink,table, counter or bathroom.
 57. A method according to claim 54, whereinthe surface comprises a medical or surgical instrument or device, atransportation vehicle, or an eating utensil.
 58. A method according toclaim 54, wherein the surface comprises a porous surface.
 59. A methodaccording to claim 58, wherein the porous surface comprises paper orfabric.
 60. A method according to claim 54, wherein the surfacecomprises a floor.
 61. A method according to claim 53, wherein thesurface is a floor coated with an intermediate coating comprising anacrylic or urethane floor finish and a topcoat comprising a UV curablefloor finish, and the polar solvent comprises benzyl alcohol.
 62. Amethod of removing soil from or reducing the antimicrobial population ofa surface by contacting the surface with an aqueous dispersion of asolvent which forms split laminar phases following contact with thesurface, wherein a film phase containing primarily solvent lies adjacentthe surface and a film phase containing primarily water lies over thefilm phase containing primarily solvent.
 63. A method according to claim62, wherein the film phase adjacent the surface also comprises anantimicrobial or biocidal agent.